Technical Abstract:
Genotypic and allelic frequencies of a single nucleotide polymorphism (SNP), in the transient receptor potential protein 1 (TRPC1) gene, were determined in Senepol (n =60), Charolais (n = 62), Angus (n = 39), Charbray (n = 43), Brahman (n = 19), Zebu (n=17) and crossbred bulls (n = 132). Association of this SNP with growth traits was assessed in a subset of the population comprising Senepol, Charolais and Senepol×Charolais bulls (n=113). Carcass data was obtained from a subset of 24 crossbred bulls. Genotypic frequencies were 0.81, 0.17 and 0.02 for CC, CG, and GG, respectively. Allelic frequencies were 0.89 and 0.11 for C and G respectively. Frequency of the C allele was greater in Charolais (P<0.1), Senepol (P<0.1), Angus (P<0.1) and crossbred bulls (P<0.05) than the G allele. In Charbray, Brahman and Zebu animals only the C allele was observed. Animals inheriting the CC genotype had heavier Gluteus medius and Gastronecmius muscle weights than animals inheriting the GG genotype (P<0.05). An association (P<0.05) was also established between the marker and estimated weight gains per day at 205 and 240 days, weight at 205 days and weaning weight. Animals inheriting the CC genotype grew faster than those inheriting the CG or GG genotypes. Evaluation of the findings from this study in larger populations needs to be ascertained before it could be used in selection schemes.